For the mass production of useful products such as amino acids, regulation of glucose uptake and pentose phosphorylation pathway in the Corynebacterium strain is very important (Handbook of Corynebacterium glutamicum. 2005. 215-240).
Gluconate repressor (GntR) is an important regulatory protein that regulates carbon flow through glucose uptake and pentose phosphorylation pathways. It is known that two gluconate repressors (GntR1 and GntR2) are found in the Corynebacterium glutamicum strain.
GntR1 and GntR2 strongly inhibit the expression of genes encoding gluconate permease (gntP), gluconate kinase (gntK), and 6-phosphogluconate dehydrogenase (gnd) which are related to gluconate metabolism, and serve a role of weakly inhibiting the expression of tkt-tal-zwf-opcA-devB operon, which is a major gene of the pentose phosphorylation pathway. Meanwhile, the expression of genes encoding glucose-specific transporter enzyme II (ptsG) and sucrose-specific transporter enzyme II (ptsS) of phospho-transferase system (PTS), which is a major sugar-infusion metabolic pathway of the Corynebacterium strain, is promoted to be significantly involved in sugar infusion (Julia Frunzke, Verena Engels, Sonja Hasenbein, Cornelia Gatgens and Michael Bott, Molecular Microbiology (2008) 67(2), 305-322).